Spin temperature treatment of cross relaxation in low fields

Abstract

Spin lattice relaxation in low fields can be measured by means of an adiabatic field cycling procedure. For the case of samples containing two nuclear species one of which is quadrupolar, cross relaxation mechanisms become important. A spin temperature treatment of the cross relaxation is given. The theoretical predictions are illustrated with experimental results for methyl anthracene and imidazole. In addition a simple experiment is described which supports the analysis and gives the frequency of one of the quadrupole resonance lines of imidazole.